Recovery from a heart attack is most often focused on lifestyle changes to support and protect cardiovascular health. But researchers out of the Johns Hopkins University School of Medicine have sounded another alarm, finding that people who had suffered a heart attack experienced a more rapid decline of brain health in the years that followed than those who were heart-healthy. And they’re not exactly sure what's driving it.
In the most comprehensive study of its kind looking at the link between heart and brain health, the health data of 30,465 people who had experienced cardiac arrest and had also completed repeated cognition tests was analyzed. The records, which spanned 1971 to 2019 and tracked patients for an average of 6.4 years, indicated that across the board, there was a much steeper cognitive decline in the heart-attack cohort than what’s expected in an aging population.
What’s more puzzling is that the slip in cognition, memory and executive function – the three markers in the study – was not immediately evident following the heart attack, but was increasingly significant over time. While there were some differences in each marker, overall cognitive decline equated to being six to 13 years more advanced than the norm.
“Due to the fact that many people are at risk for having a heart attack, we hope that the results of our study will serve as a wake-up call for people to control vascular risk factors like high blood pressure and elevated cholesterol as soon as they can since we have shown that having a heart attack increases your risk of decreased cognition and memory later on in life,” says Dr Michelle Johansen, an associate professor of neurology at Johns Hopkins.
The heart and brain health connection is an area of huge interest for scientists right now, yet the mechanisms driving those links are not well understood. In a response to the study, also published in JAMAL Neurology, scientists suggested that cognitive decline could stem from many conditions: ischemic cardiomyopathy, post-attack arrhythmias like atrial fibrillation, which has already been linked to dementia, chronic inflammation, and depression, which heart attack patients are at a greater risk of, and which has also been linked to dementia.
They also suggest future studies look into neuroimagery in relation to white matter hyperintensities (WMH), cerebral blood flow and regional brain atrophy in patients that had recovered from heart attacks.
The Johns Hopkins team now plans to look more broadly at heart health and how it impacts brain function. They also hope these findings may help medical professionals inform at-risk patients of the myriad wide-ranging negative health impacts that come with the progression of heart disease.
"We have shown that preventing heart attacks may be one strategy to preserve brain health in older adults," Johansen said. "Now we need to determine what specifically is causing the cognitive decline over time."
According to the Centers for Disease Control and Prevention, more than 800,000 people in the US have a heart attack each year.
The study was published in the journal JAMA Neurology.
